[PATCH] ARM: Add Kconfig entry for SG chain support

[Fernando Guzman Lugo]

Add a entry to make possible SG chaining under ARM
architecture.

Tidspbridge driver needs SG chaining, however SG chain has not
been tested under all platforms. Adding this option OMAP
platform can enable it and if other platforms have issues they
would not enable it.

This patch is base on this discussion:

http://marc.info/?l=linux-arm-kernel&m=129166415415541&w=2

Signed-off-by: Fernando Guzman Lugo <fernando.lugo at ti.com>
---
 arch/arm/Kconfig                   |    6 ++++++
 arch/arm/include/asm/scatterlist.h |    4 ++++
 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index dd944bd..f5cfd42 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1017,6 +1017,12 @@ config CPU_HAS_PMU
 	default y
 	bool
 
+config ARM_SG_CHAIN
+	bool "Enable SG chain support"
+	default n
+	help
+	  Enable support for SG chaining for ARM
+
 if !MMU
 source "arch/arm/Kconfig-nommu"
 endif
diff --git a/arch/arm/include/asm/scatterlist.h b/arch/arm/include/asm/scatterlist.h
index 2f87870..eab7c4f 100644
--- a/arch/arm/include/asm/scatterlist.h
+++ b/arch/arm/include/asm/scatterlist.h
@@ -5,4 +5,8 @@
 #include <asm/types.h>
 #include <asm-generic/scatterlist.h>
 
+#ifdef CONFIG_ARM_SG_CHAIN
+#define ARCH_HAS_SG_CHAIN
+#endif
+
 #endif /* _ASMARM_SCATTERLIST_H */
-- 
1.6.3.3